San Diego  Homicide detectives are investigating the death of a man who was found lying on a sidewalk in City Heights early Friday morning.

A person driving by discovered the victim about 3:40 a.m. on the southeast corner of University Avenue and 39th street, San Diego police homicide Lt. Kevin Rooney said.

Paramedics performed CPR on the man but he could not be revived and was pronounced dead, Rooney said.

Detectives said the man appeared to have been stabbed, Rooney said.

He has not been identified but it appears he was in his 50s, the lieutenant said. He had a large black gym bag with him.

Blue evidence markers marked a blood trail that led south on 39th and ended about three-quarters of the way down the block, which contains a mix of single-family homes and apartment buildings.

Residents there reported hearing the sounds of a fight about an hour before the man was found, Rooney said.

University Avenue was shut down in both directions between 40th and 38th streets. The westbound lanes of the busy roadway were reopened at 9:30 a.m. while the eastbound lanes remain closed until further notice.

Anyone with information is asked to call homicide detectives at (619) 531-2293 or leave an anonymous tip with Crime Stoppers at (888) 580-8477 or sdcrimestoppers.com.